A wide variety of terminal blocks are known in the prior art which have a plurality of connection terminals and can be used for a wide range of different purposes. For example, terminal blocks are known which are designed as panel feedthrough terminals and are suitable for connecting electric lines for photovoltaic systems. In these and also in other cases it may be expedient to prevent the actuation of a switch or of a lever terminal. An appropriate protection element or a sealing means can be used for this purpose so that an unwanted actuation is made more difficult or an undetected actuation is prevented.
In order to simultaneously protect a plurality of actuation elements against an unwanted and unauthorized actuation, a housing can be provided around all of the elements, which prevents access to the actuation elements. Such a system does work but has the disadvantage that the state of the individual actuation elements is not directly visible and that, in addition, there is a high assembly cost.